Fluid pulse generators

ABSTRACT

A radial piston type pulse generator divided into two axially spaced sets of radial pistons moved radially by orbiting operator means including separate rotary cams offset on opposite sides of a camshaft. The phase order is staggered so that in the sequence of operation each piston is followed in order by a piston that is substantially diametrically opposite it and which is a piston of the other set.

United States Patent McGeenmm...

Primary Examiner- Martin P. Schwadron Assistant Examiner-A. M. Zupcie m m t. "We -vl 8 M P SIT 08 LLH 2263 4556 9999 llll. l/l/ 2 22 .i 1 11 1 3655 ,1 6055 0003 1 2223 a H a r. t. S U A m .l n a m S a T mm 9 new 6 9 Sn 1 BmM4 mu vnu v 3-l70 DKaoN r 0 m 6 MM v h AF .l] 2 2 7 22 vi iii [45] Patented Junel,l97l

James S. Robbins and Associates, Inc. Seattle, Wash.

Attorney-Graybeal, Cole and Barnard [73] Assignee Division of Ser. No. 754,322, Aug. 21. 1968.

[54] FLUID PULSE GENERATORS 4 Claims, 4 Drawing Figs.

ABSTRACT: A radial piston type pulse generator divided into two axially spaced sets of radial pistons moved radially by orbiting operator means including separate rotary cams offset on opposite sides of a camshaft. The phase order is staggered so that in the sequence of operation each piston is followed in order by a piston that is substantially diametrically opposite it and which is a piston of the other set.

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PATENTED JUN 1 l97| SHEET 1 BF 3 I'll I.

DAVID B. sucosu INVENTOR.

ATTORNEYS PATENTEBJUH 11971 3.581.600

SHEET 2 [1F 3 DAVID B. SUGDEN INVIENTOR.

BY WW M ATTORNEYS Cross Reference to Related Applications This is a division of my copending application Ser. No. 754,322, filed Aug. 21, 1968, and entitled Vibrator Systems and Rock Cutter Type Utilization Mechanisms.

BACKGROUND OF THE INVENTION Field of the Invention This invention relates to orbiting radial force pulse type, and in particular to the provision of a pulsator systems specific pulse generator for use in such systems.

SUMMARY OF THE INVENTION In preferred form the pulse generator of this invention is used to drive a vibrator type mechanism characterized primarily by an orbiting small mass member supported on a relatively large mass backup structure, which is adapted to itself orbit whenever the small mass member is prevented from moving by a restraining load, and to transmit a high inertial force created by its movement through the small mass member to whatever load is tending to restrain such small mass member against movement. The large mass backup structure includes a mounting member for the small mass member and the small mass member is free for 360 of limited radial movement relative to its mounting member. The pulse generator of this invention generates short duration radial force pulses between the members, for cycling the pulses throughout the 360. This causes an orbital movement of the small mass member when it is not restrained. However, when the small mass member is loaded to the extent it is at least partially restrained from moving, the cycling force pulses operate to orbit the backup structure.

At present the principal interest in the above described vibrator system is its adaptability to earth mining operations, and in particular to hard rock cutting. Accordingly, the small mass member may take the form of a cutter wheel having a peripheral cutting edge, with the large mass backup structure being an earth mining or boring machine, eg the type shown by FIG. 3 of the aforementioned US. Pat. No. 3,235,131 1; the type disclosed by US Pat. No. 3,232,670, issued Feb. 1, 1967 to Richard .1. Robbins et al. or the type disclosed by US. Pat. No. 3,200,494, issued Nov. 30, l965 to Robert E. Cannon et al.

According to this invention, a rotating force field is established by a pulsator type fluid system in which the orbiting cutter wheel and its mounting member are principal components of the pulse receiver, and such pulse receiver includes a ring of variable volume fluid chambers which receive fluid pressure pulses from a pulse generator having a like number of variable volume chambers, each of which is coupled to one of the chambers of the pulse receiver. In operation, columns of a substantially incompressible fluid are moved back-and-forth through conduits interconnecting between the variable volume chambers of the generator and the corresponding variable volume chambers of the receiver, primarily by an energy input into the generator. According to the invention, the pulse generator comprises two axially spaced apart sets of angularly equally spaced apart, radially oriented, piston chambers. Each set comprises a number of piston chambers equal to one-half of the number of variable volume fluid chambers. Each piston chamber of each set is angularly centered between two angularly adjacent piston chambers of the other set. The pistons are moved by orbiting operator means which is in contact with the inner portions of the pistons. During orbiting movement there is a successive outward and then inward movement of the pistons. The orbiting operator means is arranged to establish a staggered phase order between both the sets of pistons and diametrically across the generator. As a result, in the sequence of operation each piston is followed in order by a piston that is substantially diametrically opposite it and which is a piston of the other set. In this way the radial loads on the generator are partially balanced.

Each piston chamber includes an inlet-outlet passageway leading from it which is smaller in diameter than the piston chamber. Each inlet-outlet passageway is surrounded by radially inwardly directed fluid port means which is associated with a source of make-up fluid under pressure. An annular washerlike valve member is located radially inwardly of the port means. An annular spring means, in the form of a bowed washer, is supported radially between the outer end of the piston chamber and said valve member. This spring means normally urges the valve member radially outwardly into a position wherein it closes the port means. The port means stays closed until the pressure within the piston chamber falls below a level whereat such pressure and the spring pressure together are exceeded by the pressure of the make-up fluid. When this happens the make-up fluid moves the valve member inwardly, allowing some make-up fluid to flow into the piston chamber.

BRIEF DESCRIPTION OF THE DRAWING Reference is now made to the accompanying illustrations of certain embodiments of the invention, wherein like numerals refer to like parts, and wherein:

FIG. 1 is a cross-sectional view of a pressure pulse generator typifying the invention, taken substantially along line 1-1 of FIG. 3;

FIG. 2 is a cross-sectional view of the pressure generator, taken substantially along line 2-2 of FIG. 3;

FIG. 3 is an axial sectional view, taken substantially along line 3-3 of FIG. 1; and

FIG. 4 is a fragmentary perspective view taken in the region of contact between the base portion of one of the pistons and the associated flat peripheral surface of the piston operator, showing the guide element which prevents rotation of the piston.

A preferred form of pulse generator is shown by FIGS. 1-3 to comprises a main body in the nature of an open centered block 93 having forming therein two axially spaced banks of radial piston chambers, each preferably in the form of a cylindrical bore 100. Each chamber is equipped with a piston having a cylindrical portion 102 snugly received in its bore or chamber 100, and a flanged base 104. The pistons 102 are fitted into the bores 100 from the space within the body. A countersink 106 is provided in the body in the region of the outlet from each piston chamber 100. A tubular inner portion 108 of an inlet-outlet fitting 110 is received in the countersink 106, and the fitting 110 is secured to the body by means of a pair of cap screws 112. A small bore 114 extends axially through the inner end portion of the fitting and a slightly large diameter bore 1116 continues therefrom and extends through the remaining portion of the fitting. The end of a conduit 118 which communicates the piston chamber with its associate pulse chamber in the pulse generator fits into each outer bore 116. An annular chamber 120 is formed in the inner portion of the fitting about the inner bore 114, and a relatively narrow gap passageway 122 extends inwardly from each said chamber 120 and terminates in an annular outlet which is generally flush with the inner end of the fitting, and is bordered on each side by a flat end surface of the fitting.

Referring now to FIG. 3, an annular :manifold 124 is formed in the left (as pictured) end plate 126. A fluid delivery port, shown in the nature of a bore 128 formed axially through the radially outer portion of the body, communicates the annular manifold with an annular passageway 130 surrounding the inner end portion of the fitting, and such annular passageway 130 is in communication with the annular chamber 120.

The annular outlet from each passageway 122 is normally closed by a flat washer valve 132 which is normally biased outwardly by a washer like spring 134. The spring 134 is sandwiched between the the movable washer valve 132 and a fixed washer 136 which is firmly anchored to the body 98 near the outlet of its piston chamber. As shown, the spring 134 is in the nature of a bowed washer. It is resilient enough that it will flatten out when subjected to enough pressure by the washer like. O-rings 144, 146 are inset into the body on the radial inner and outer sides of the annular manifold 124. The end plates 126, 126 have open centers for receiving roller bearings 148 or the like which surroundingly engage and support for rotation a drive shaft 150. The drive shaft 150 is shown to include two outwardly extending, splined and portions 152, 154, one of which is connected to an electric motor or other prime mover (not shown). The opposite end of the shaft may be secured to one end of a similar pulse generator, so that both of the generators can be powered by a single drive mechanism. In the usual fashion, a seal assembly 158, including an annular seal member 160 which surroundingly engages the shaft 150 immediately outwardly of the bearing, is secured to each end plate 126, 126,

lnteriorly of the body the shaft includes a pair of circular cams 162, 164 which are eccentrically related to the shaft proper. As FIG. 3 and a comparison of FIGS. 1 and 2 will show, the cams 162, 164 are offset from each other generally on opposite sides of the shaft, so that the radial loadings on the shaft during operation are as close to being balanced as is possible. In the illustrated embodiment each bank of pistons comprises six pistons. The 12 pistons are phased 30 apart and are operated in the sequence depicted in FIG. 1, using for each piston the number of its corresponding pulse chamber in FIG. 8 of the post receiver disclosed in the aforementioned parent application Ser. No. 754,322.

Referring to FIG. 3, a plate type counterweight 166, 168 is positioned axially outwardly of each cam 162, 164 and extends radially outwardly from the shaft 150 on the side thereof opposite the cam. The weights 166, 168 are sized and weighted appropriately to substantially counterbalance the centrifugal forces generated by the rotating and reciprocating parts.

As clearly shown by FIGS. 1 and 2, the inner cavity of the body 98 is in the shape of a polygon and has the same number of sides as there are pistons. In the illustrated embodiment the cavity for each bank of pistons is hexagonal. An operator member 170, 172 which has the same cross sectional shape as the cavity, but diametrically is somewhat smaller, snugly surrounds each cam 162, 164 and is moved thereby. The flat inner end surfaces of the pistons abut the flat peripheral surfaces of the operators 170, 172. The cavities and the shaft 150 have the same center, but he center of the cams 162, 164 is offset from the center of rotation. As a result, the cams 162, 164 shift the operators 170, 172 around the periphery of the cavity as the shaft 150 rotates. As the operators shift they sequentially displace the pistons outwardly and permit sequential return of the pistons.

Guide clips 174 (FIG. 13) may be secured to the side surfaces of the operators closely adjacent the bases of the pistons, such clips 174 each including a pair of guide fingers 176 which loosely project over outer surface portions of the flanged bases. The clips 174 prevent unwanted rotation of the pistons but at the same time permit the relative sliding motion between the piston bases 1M and the operators 170, 172 which wants to occur while the operator is shifting. The fingers 176 also help to return the pistons during the phases the operator movement is radially inwardly.

As illustrated in FIGS. 1 and 2, cavities are provided in the operators 170, 172 between them and the cams 162, 164, and in the inner end surfaces of the pistons, between them and the operators 170, 172. These cavities are in constant communication with the pressure chamber, via meter orifice containing ports 180. 182, so that a balancing fluid cushion exits where linear sliding occurs between the pistons and the operators 170, 172 and where rotational movement occurs between the cams 162, 164 and the operators 170, 172.

The limits of the invention will now be measured by the following claims.

I claim:

1. A pressure generator for operating a fluid device of a type having a plurality of successively and sequentially filled and emptied variable volume fluid chambers, each of which includes a combined inlet-outlet opening, said generator comprising:

open centered housing means defining at least one set of equally spaced apart radially oriented piston chambers, each said piston chamber including an outwardly directed inlet-outlet passageway smaller in diameter than said piston chamber;

a piston in each said piston chamber, each said piston having an inner portion which extends into the open center of the body;

orbiting operator means within the center portion of said I body in contact with the inner portions of the pistons, and during orbiting movement successively displacing the pistons outwardly and permitting successive inward return of the pistons after such pistons have reached their outer limits of travel;

fluid port means around each inlet-outlet passageway and directed radially inwardly into the associated piston chamber;

a valve member for covering said fluid port means, said member being positioned radially inwardly of said fluid port means;

spring meansradially inwardly of said valve member and normally urging said valve member radially outwardly to close said port means; and

a source of make-up fluid under pressure in communication with the side of said valve member opposite said spring means, so that the valve means will open and permit the flow of make-up fluid through said port means and into the piston chamber whenever the combined pressure of the fluid in the piston chamber and the spring are exceeded by the pressure of said make-up fluid.

2. A pressure generator according to claim 1, wherein said valve member is annular and said spring means is annular and bowed, and the openings in said valve member and said spring means are aligned between the piston chamber and the inletoutlet passageway.

3. A pressure generator for operating a fluid device of a type having an even number plurality of successively and sequentially filled and emptied variable volume fluid chamber, each of which includes a combined inlet-outlet opening, said generator comprising:

open centered housing means defining two axially spaced apart sets of angularly equally spaced apart, radially oriented, piston chambers, each set comprising a number of such piston chambers equal to one half of the number of said variable volume fluid chambers, each piston chamber of each set being angularly centered between two angularly adjacent piston chambers of the other set, and each said piston chamber including an outwardly directed inlet-outlet opening;

a piston in each said piston chamber, each said piston having an inner portion which extends into the open center of the body;

orbiting operator means within the center portion of said body in contact with the inner portions of the pistons, and during orbiting movement successively displacing the pistons of each set outwardly and permitting successive inward return of the pistons of each set after such pistons have reached their outer limits of travel, said orbiting operator means establishing a staggered phase order between both the sets of pistons and diametrically across the generator, so that in the sequence of operation each piston is followed in order by a piston that is substantially tary shaft, two eccentric circular cams on said shaft, one for each set of pistons, and a ring member surrounding each cam and having a polygonal peripheral shape with sides equal in number with the pistons and with each side in sliding and pushing contact with the inner portion of its pistons, and with each circular cam being sized to rotate within its ring member during rotation of the shaft. 

1. A pressure generator for operating a fluid device of a type having a plurality of successively and sequentially filled and emptied variable volume fluid chambers, each of which includes a combined inlet-outlet opening, said generator comprising: open centered housing means defining at least one set of equally spaced apart radially oriented piston chambers, each said piston chamber including an outwardly directed inlet-outlet passageway smaller in diameter than said piston chamber; a piston in each said piston chamber, each said piston having an inner portion which extends into the open center of the body; orbiting operator means within the center portion of said body in contact with the inner portions of the pistons, and during orbiting movement successively displacing the pistons outwardly and permitting successive inward return of the pistons after such pistons have reached their outer limits of travel; fluid port means around each inlet-outlet passageway and directed radially inwardly into the associated piston chamber; a valve member for covering said fluid port means, said member being positioned radially inwardly of said fluid port means; spring means radially inwardly of said valve member and normally urging said valve member radially outwardly to close said port means; and a source of make-up fluid under pressure in communication with the side of said valve member opposite said spring means, so that the valve means will open and permit the flow of make-up fluid through said port means and into the piston chamber whenever the combined pressure of the fluid in the piston chamber and the spring are exceeded by the pressure of said make-up fluid.
 2. A pressure generator according to claim 1, wherein said valve member is annular and said spring means is annular and bowed, and the openings in said valve member and said spring means are aligned between the piston chamber and the inlet-outlet passageway.
 3. A pressure generator for operating a fluid device of a type having an even number plurality of successively and sequentially filled and emptied variable volume fluid chamber, each of which includes a combined inlet-outlet opening, said generator comprising: open centered housing means defining two axially spaced apart sets of angularly equallY spaced apart, radially oriented, piston chambers, each set comprising a number of such piston chambers equal to one half of the number of said variable volume fluid chambers, each piston chamber of each set being angularly centered between two angularly adjacent piston chambers of the other set, and each said piston chamber including an outwardly directed inlet-outlet opening; a piston in each said piston chamber, each said piston having an inner portion which extends into the open center of the body; orbiting operator means within the center portion of said body in contact with the inner portions of the pistons, and during orbiting movement successively displacing the pistons of each set outwardly and permitting successive inward return of the pistons of each set after such pistons have reached their outer limits of travel, said orbiting operator means establishing a staggered phase order between both the sets of pistons and diametrically across the generator, so that in the sequence of operation each piston is followed in order by a piston that is substantially diametrically opposite it and which is a piston of the other set, whereby the radial loads on the generator are partially balanced; and a separate combined fluid delivery and return passageway extending between the inlet-outlet opening of each piston chamber and the inlet-outlet opening of a related one of the variable volume chambers of the fluid device.
 4. A pressure generator according to claim 3, wherein the orbiting operator means for each set of pistons comprises a rotary shaft, two eccentric circular cams on said shaft, one for each set of pistons, and a ring member surrounding each cam and having a polygonal peripheral shape with sides equal in number with the pistons and with each side in sliding and pushing contact with the inner portion of its pistons, and with each circular cam being sized to rotate within its ring member during rotation of the shaft. 